Perhaps you should try some spelling variations:
thieu sang » thieu khang, thieu quang, nhieu tang
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
tinh sinh » tinh ninh, tinh binh, tinh hinh
hang cong » dang cong, hang nong, bang cong
cong manh » cong danh, duong manh, cong thanh
manh toan » thanh toan, anh tuan, tinh toan
vat hang » van hang, dat hang, va hang
toan ban » van ban

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu sang) or (((chieu sang) OR (hieu lang)))) - tinh sinh vat hang cong manh toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (((chieu sang) OR (hieu lang)))) - tinh sinh vat hang cong manh toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (((chieu sang) OR (hieu lang)))) - tinh sinh vat hang cong manh toan ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (((chieu sang) OR (hieu lang)))) - tinh sinh vat hang cong manh toan ban*.